Preparing yeast for use in food products



Patented Mar. 9, 1926. A a

' V, UNITED STATES 1,575,762 PATENT, QF'F lCE. 1

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To-all whom it may concern:

Be it known-that we, CHARLES HOFFMAN,

a citizen of the United States, residim at Tuckahoe, Westchester County, New l ork 5 State, and CHARLES N. FREY, a citizen of the United States, residing at Warren, TrumbullCounty, State of Ohio, have invented certain new and useful Improvements in Preparin Yeast for Use in Food Products; and we 0 hereby declare the followin to be a full, clear, and exact description 0 the invention such as will enable others skilled in the art to which it appertains to make and use the same.

In the co-pending application of Charles Hoffman, Serial No. 662,988filed September 15, 1923 there is described an improved bread wherein the vitamin-B deficiency is supplied and the nutritive value of the bread otherwise improved by the addition of yeast other than that employed for leavenin the bread. As pointed out in that a licatlon, in order for yeast to be suitag e for this use it must have its cell walls unruptured and must also be inactive in so far as the fermentation and maturing effects on the gluten of the dough are concerned. p The invention of the present case relates 39 to method of rodueing a yeast preparation having the above-mentioned qualities and ptherwise suitable for use in bread for its nutritive value and its high vitamin content, 'and the object of the invention is to prov vide a process whereby a yeast pre aration having such qualities may be pr need in a simple, efiicient and economical manner.

The invention of this application also includes the yeast preparation itself as a food 40 product for direct consumption or for use In bread or other foods.

The activity of the yeast cells may be destroyed by the application of suflicient heat in drying, the degree of heat necessary to quickly dry the yeast and destroy its activity being insuflicient to materially impair the vitamin-B content. Such rapid drying, however, is liable to rupture thewall of the yeast cell unless carried out under sub-atmospheric pressure. we therefore preferably dry the yeast in a vacuum drum drier such as largely employed for the production of milk powder. In such an apparatus the moisture in the yeast cell is largely Application filed September 15, 1923. Serial No. 662,989.

even when the latter are unruptured. The

least dried without redzreatment will, when dissolved in liquid in the mixing of the bread, allow the escape of some of the nitrogenous matter, particularly the amino acids which in quantities desired in bread manufacture impart a bitter taste and discoloration of the bread, and also certain of the enzyme ingredients of the yeast cell may escape which mayadversely affect the fermentation of the dou-h. We have found, however, that the drie yeast product produced by the vacuumdrum drying procass as above described can be materially improved by treating the 'yeastin' such' manner as to coagulate the roto lasmic material within the yeast cel sue coagulation serving to substantially prevent the escape B0 of any art of the yeast cell content when dissolved in water or added to bread.

One methodof so treating the yeast prior to drying is to add to it a saturated solution of ammonium sulfate, a quantity of as such solution x of from one-half to full weight of the yeast weighed as ordina I commercial comp yeast) being The yeast and ammonium sulfate mixture is heated to ap roximately 85-C. and is our then filtered and dried as above. described, at least a portion of the ammonium sul hate washed out prior to drying, de- 81 In lieu of using the saturated solution of 96 ammonium sulfate as above described, a dilute acid such as hosphoric, aceti or citric, ma be used. ery good results ave been pro need by using the above acids dilubed to 5% concentration, the amount of the diluted acid being about ual to the wei ht of the yeast to be trea Sulfuric 86k? may also be employed in the same way, referably a 1 or 2% acid employ The solution is heated as above described and the material filtered and dried.

The acid-treated yeast is not quite so suitable for the manufacture of bread as-the yeast treated with ammonium sulfate. The acid-treated yeast cannot be mixed withthe dough while dry without producing discoloration and noticeable vflavor and odor. If used wet, the acid-treated yeast will produce a fair quality of bread without noticeable flavor or odor of the yeast. The ammonium sulfate-treated yeast may be used dried or wet and does not affect the color or flavor of the bread.

When the above-described re treatment is employed, the step of heating with the acid or sulfate substantially destroys the life of the yeast plant so that the yeast may be dried at low temperatures in open trays if desired. We prefer, however, to drumdry the yeast in any case, as it is easier to prevent contamination of the yeast during the drying process, and is in most circumstances a more economical process, due to the large area required for tray-drying on a large scale.

Having described our invention, what we claim as new and desire to secure by Letters Patent, is W 1. The process of treating yeast which consists in devitalizing the east and drying without rupturing the 'ce walls. 1

2. The process of treating yeast which :onsists in coagulating the rotoplasmic material of the yeast cells, devitalizing the yeast and dryingwithout rupturing the cell walls.

3. A process of treating yeast which consists in subjecting the yeast to the action of a substance adapted to coagulate the protoplasmic material, heating to'divitalizethe yeast, and drying without rupturing the cell walls.

' plasmic .material, heating to devitalize the yeast, and drying without rupturing the cell walls.

5. Theprocess of treating yeast which consists in subjecting the yeast to the action of an ammonium salt and devitalizing and drying .without rupturing the cell walls.

6. The "process of treating yeast which consists in subjecting the yeast to the action of ammonium sulfate and devitalizing and drying without rupturing the cell walls.

7. The step in the process of treating yeast which consists in treating the yeast with a saturated solution of ammonium sulfate, heating the solution to substantially 85 C. and then filtering and drying.

8:The steps in the process of treating yeast which consist in treating the yeast with a saturated solution of ammonium sulphate, heating to substantially 85 (1, removing at least a portion of the ammonium sulphate by washing, and then filtering and drying without rupturing the cell walls.

9. The steps in the process of treating yeast which consist in treating the yeast with ammonium sulphate and heating todevitalize the yeast without rupturing the cell walls.

10. As a food product, a devitalized dried yeast with the walls of the yeast cells substantially unruptured.

11. As a food product, a devitalized dried yeast with the walls of the yeast cells substantially unruptured, and with the protoplasmic material in the cells coagulated.

12. As an improved product, a devitalized yeast, with the walls of the yeast cells substantially unruptured and with the protoplasmic material in the cells coagulated,

which is admixed with ammonium sulphate.

In testimony whereof we atlix our signatures.

CHARLES HOFFMAN. CHARLES N. FREY.

yeast treated with ammonium sulfate. The acid-treated yeast cannot be mixed with the dough While dry without producing discoloration and noticeable flavor and odor. If used wet, the acid-treated yeast will produce a fair quality of bread without noticeable flavor or odor of the yeast. The ammonium sulfate-treated yeast may be used dried or wet and does not affect the color or flavor of the bread.

\Vhen the above-described pretreatment is employed, the step of heating with the acid or sulfate substantially destroys the life of the yeast plant so that the yeast may be dried at low temperatures in open trays if desired. \Ve pret'er, however, to drumdry the yeast in any case, as it is easier to prevent contamination of the yeast during the drying process, and is in most circumstances a more economical process, due to the large area required for traydrying on a large scale.

Having described our invention, what we claim as new and desire to secure by Letters Patent, is

1. The process of treating yeast which consists in devitalizing the yeast and drying without rupturing the cell walls.

2. The process of treating yeast which :onsists in coagulating the protoplasmic material of the yeast cells, devitalizing the yeast and drying without rupturing the cell walls.

3. A process of treating yeast which consists in subjecting the yeast to the action of a substance adapted to coagulate the protoplasmic material, heating to divitalize the yeast, and drying without rupturing the cell walls.

4. A process of treating yeast which consists in subjecting the yeast to the action of a salt adapted to coagulate the protoplasmic material, heating to devitalize the yeast, and drying without rupturing the cell walls.

5. The process of treating yeast which consists in subjecting the yeast to the action of an ammonium salt and devitalizing and drying without rupturing the cell walls.

6. The process of treating yeast which consists in subjecting the yeast to the action of ammonium sulfate and devitalizing and drying without rupturing the cell walls.

7. The step in the process of treating yeast which consists in treating the yeast with a saturated solution of ammonium sulfate, heating the solution to substantially 85 C. and then filtering and drying.

8.The steps in the process of treating yeast which consist in treating the yeast with a saturated solution of ammonium sulphate, heating to substantially 85 C, removing at least a portion of the ammonium sulphate by washing, and then filtering and drying without rupturing the cell walls.

9. The steps in the process of treating yeast which consist in treating the yeast with ammonium sulphate and heating to dex'itallize the yeast without rupturing the cell wal s.

10. As a food product, a devitalized dried yeast with the walls of the yeast cells substantially unruptured.

11. As a food product, a devitalized dried yeast with the walls of the yeast cells 'sulmtantially unruptured, and with the pro lOPllSlTllC material in the cells coagulated.

12. As an improved product, a devitalized yeast, with the walls of the yeast cells substantially unruptured and with the protoplasmic material in the cells coagulated, which is admixed with ammonium sulphate.

In testimony whereof we affix our signatures.

CHARLES HOFFMAN. CHARLES N. FREY.

Gertificate of Correction.

It is hereby certified-that in Letters Patent No. 1,575,762, granted March 9, 1926, u n the appgcation of Charles Hofiman, of Tuckahoe, New York, and Charles Frey, of

arren, Ohio, for an improvement in Preparing Yeast for Use in Food Products, errors appear in the printed specification requiring correction as follows: Page 1, line 64, for the word least read yeast, and line 91, after the word then insert the word cooled; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record oi the case in the Patent Office.

ed and sealed this 13th day of April, A. D. 1926.

[sun] M. J. MOORE, Acting Commissioner of Patents.

Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,575,762, granted March 9, 1926,

upon the apolication of Chttrles Hoffman, of Tuckahoe, New York, and Charles N. Frey, of Warren, Ohio, for an improvement in Preparing Yeast for Use in Food Products, errors appear in the printed specificati n requiring correction as follows: Page 1, line 64, for the word least read yeast, and line 91, after the Word then insert the word cooled, and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 13th day of April, A. D. 1926.

[emu] M. J. MOORE,

Acting Commissioner of Patents. 

